..in addition to applying several unrelated qmail patches, we have changed how the mail server accepts mail. It used to allow relaying (that is, sending on of mail) if the sending IP address had authenticated with the IMAP server within the last 60 minutes, but this proved to be a nasty hack for several reasons.

Now, the mail server will deliver mail if you authorize with it directly first, using SMTP AUTH.

Most mail clients support this. Please look for options like this:

Mail server: mail.icculus.org

Use encryption: Always

Use authentication: Always

Authentication type: "PLAIN".

You will be prompted for your email account's password when sending mail (many mail clients will have a "remember my password" button if this is a pain in the butt). This password is the same one you use to check your mail in the first place.